CN100437705C - Organic EL drive circuit, reference current generator circuit and organic EL display device - Google Patents
Organic EL drive circuit, reference current generator circuit and organic EL display device Download PDFInfo
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- CN100437705C CN100437705C CNB2005100689602A CN200510068960A CN100437705C CN 100437705 C CN100437705 C CN 100437705C CN B2005100689602 A CNB2005100689602 A CN B2005100689602A CN 200510068960 A CN200510068960 A CN 200510068960A CN 100437705 C CN100437705 C CN 100437705C
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
- G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
- G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
- G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
- G09G3/3208—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED]
- G09G3/3275—Details of drivers for data electrodes
- G09G3/3283—Details of drivers for data electrodes in which the data driver supplies a variable data current for setting the current through, or the voltage across, the light-emitting elements
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
- G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
- G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
- G09G3/3208—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED]
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2320/00—Control of display operating conditions
- G09G2320/04—Maintaining the quality of display appearance
- G09G2320/041—Temperature compensation
Abstract
A first current mirror circuit including an input side transistor, an output transistor and passive elements respectively connected in series with said input side transistor and said output side transistor, temperature coefficients of said passive elements being opposite in characteristics and a second current mirror circuit provided as a load circuit of the first current mirror circuit, for feeding back an output current of the output side transistor to an input of the input side transistor are provided. A drive current is generated on a basis of a current corresponding to a current generated in the output side transistor as a reference current and an operating current ratio of the input side transistor and the output side transistor is selected such that luminance change of organic EL elements with respect to temperature change is restricted.
Description
Technical field
The present invention relates to a kind of reference current generator circuit of organic EL drive circuit, a kind of organic EL display apparatus that uses the organic EL drive circuit of same reference current generator circuit and use same organic EL drive circuit.Especially, the present invention relates to a kind of reference current generator circuit of display device of the electric equipment that is used for mancarried telephone device for example or PHS, it is suitable for being applied in the colored demonstration of high brightness aspect, and, use it to make the white equilibrium of display device constant in wider temperature range by the loss that prevents white equilibrium (white balance) owing to change the temperature environment of display device.
Background technology
The OLED panel of organic EL display apparatus is applied to mancarried telephone device, PHS, DVD player and PDA aspects such as (portable), has advised comprising individual terminals pin and 162 the terminals pins that are used for line that are used for alignment in 396 (132 * 3).The number that is used for the terminals pin of alignment and line still can increase.
The output stage of the current driving circuit of the traditional active matrix type or the OLED panel of passive matrix type comprises output circuit, it is provided to the pin of terminals separately of display board accordingly, and each output circuit is made of the driven with current sources circuit, and the driven with current sources circuit is made of for example current mirror circuit.
In addition, for constant by the white equilibrium of regulating on the display screen that brightness corresponding to the R (red) on the display screen of the organic EL material that is used for primary colours, G (green) and B (indigo plant) primary colours keeps the color organic EL display board, the current driving circuit of color organic EL display board comprises regulating circuit, is used for R separately, G on the display screen and the brightness regulation of B.
Each current driving circuit that is used for driving the organic EL of the R, the G that are used for being arranged in matrix and B color generally includes: the single reference current generator circuit that is generally used for R, G and B color, and the reference current setting circuit that provides to the correspondence of R, G and B color separately.Regulate the reference current that produces by single reference current generator circuit corresponding to the reference current setting circuit that primary colours separately provide, produce corresponding to the reference current of primary colours separately.By regulating reference current, realized the white equilibrium on the display screen by the reference current setting circuit.The reference current of regulating thus, be used for R, G and B color offered be used for the driving circuit of R, G and B color separately.
JP2001-34221A has disclosed a kind of technology, by being provided to the driving circuit of organic EL from the steady current of steady current setting circuit, and drive driving circuit with pwm pulse, organic EL is luminous, and because by regulating electric current from the steady current setting circuit so that aging the recovery reduced radiative intensity.
Usually, the electric equipment with organic EL display apparatus can operate in from-10 ℃ to+70 ℃ in the wide temperature range (temperature environment).In the wide like this operating temperature range of display device, because the variation of the environment temperature of electric equipment in such temperature range, at organic EL display apparatus particularly is that the loss of the white equilibrium on the display screen becomes problem under the high brightness color organic EL display device situation.Such loss of the white equilibrium on the display screen is caused by the following fact: the light emission characteristics of R, G and B color changes corresponding to temperature, and depends on the luminescent substance that forms organic EL.
Now, shown in the solid line among Fig. 3 (a), be used for temperature characterisitic R linear reduction of the luminescent substance of R color along with the increase of temperature.Shown in the solid line among Fig. 3 (b), the temperature characterisitic G that is used for the luminescent substance of G color is represented by the middle concave curve that near the center 0 ℃ has minimum value, and shown in the solid line among Fig. 3 (c), be used for temperature characterisitic B linear increase of the luminescent substance of B color along with the increase of temperature.
Incidentally, the ratio that Fig. 3 (a) indicates brightness Po and output current Io to the ordinate of Fig. 3 (c), i.e. the brightness of per unit drive current (Po/Io), and the horizontal ordinate indicated temperature (℃).In the operating temperature range of organic EL, the brightness Po of luminescent substance is linear with respect to output current Io usually, and the temperature characterisitic of R, G and B color has nothing in common with each other each other.
The result, if the working temperature of display device is changing in-10 ℃ to+70 ℃ operating temperature range, then may lose the white equilibrium that is arranged on central temperature on the display screen of display device, this temperature is the normal temperature in the temperature range normally, for example 25 ℃.
Summary of the invention
The reference current generator circuit that the purpose of this invention is to provide a kind of organic EL drive circuit, its brightness that can prevent organic EL display apparatus changes in the operating temperature range of this equipment broad.
Another object of the present invention provides a kind of organic EL driving circuit, and it can remain on the white equilibrium of display device in the wide temperature range, and can prevent because the loss of the white equilibrium of variation of temperature during the use display device.
Another object of the present invention provides a kind of organic EL display apparatus that uses identical organic EL driving circuit.
According to the present invention, realize above-mentioned purpose by the reference current generator circuit that a kind of organic EL driving circuit is provided, this circuit is used to produce the drive current of each terminals pin of organic EL plate, to drive organic EL plate, it is characterized in that comprising: first current mirror circuit, comprise being connected in series to input side transistor and the transistorized passive element of outgoing side respectively, and have opposite temperature coefficient; And second current mirror circuit, be set up load circuit as first current mirror circuit, be used for the transistorized output current of outgoing side is fed back to the transistorized input of input side, wherein, according to the corresponding electric current of electric current that produces with the outgoing side transistor as the reference electric current, produce drive current, and select the ratio of input side transistor and the transistorized working current of outgoing side, so that change the brightness change that confined direction is proofreaied and correct the organic EL that causes owing to its temperature variation according to brightness.
As mentioned above, in the present invention, by second current mirror circuit transistorized current feedback of the outgoing side of first current mirror circuit is arrived its input side transistor, this second current mirror circuit is the active load of first current mirror circuit, therefore, by its input side transistor, will and have the outgoing side transistor that is provided to first current mirror circuit with respect to the corresponding electric current of voltage difference between the passive element of the positive and negative temperature coefficient of temperature variation respectively.Therefore, can stably produce the big electric current with temperature coefficient, the predefined function of its Positive and Negative Coefficient Temperature by having reflected passive element is determined.Derive the big electric current of the positive and negative temperature coefficient of reflection passive element from the outgoing side transistor of first current mirror circuit, as the reference electric current.
In addition, for the direction that does not have the material change according to variation characteristic is proofreaied and correct the brightness variation characteristic of organic EL with respect to temperature, by input side transistor and the transistorized working current ratio of outgoing side of selecting first current mirror circuit, promptly, the working current ratio produces reference current.
Incidentally, by selecting the working current ratio to obtain to have the reference current of the negative temperature characteristic of the positive negative characteristic that has reflected passive element, have the reference current of the positive temperature characterisitic of the positive negative characteristic that has reflected passive element, and the reference current with positive and negative temperature characterisitic of the positive negative characteristic that has reflected passive element.
Therefore, from reference current, can obtain drive current with above-mentioned arbitrary temperature characterisitic, be used to proofread and correct the brightness of organic EL, even according to when the temperature of display device when approximately-10 ℃ in+70 ℃ of wide scopes, changing, the also almost immovable direction of the brightness of organic EL is proofreaied and correct.
Particularly, by obtaining reference current separately, it has and is used to proofread and correct the temperature characterisitic that the organic EL of R, G and B color changes with respect to the brightness of temperature, wherein according to passing through to select the working current ratio, brightness does not have material change's direction to proofread and correct, be used for to prevent the white balanced forfeiture on the color display apparatus from about-10 ℃ color display apparatus in+70 ℃ the temperature range.
As a result, prevented that in wider temperature range the brightness of color display apparatus from changing, and in the wider temperature range that color display apparatus uses, can keep the white equilibrium of color display apparatus constant.
Description of drawings
Fig. 1 is according to embodiments of the invention, the circuit structure diagram of the row driver of organic EL plate of use organic EL drive circuit;
Fig. 2 shows when the input side transistor of the current mirror circuit of forming reference current generator circuit and the transistorized channel width of outgoing side (grid width) when ratio is used as parameter, the chart of drive current temperature characterisitic; And
Fig. 3 (a) shows chart to Fig. 3 (c), is used to explain the general temperature characterisitic with respect to the output current of the luminescent substance that is used for primary colours R, G and B.
Embodiment
Among Fig. 1, reference number 10 will be listed as IC driver (hereinafter being referred to as " row driver ") and be expressed as the organic EL drive circuit that is used to drive organic EL.Row driver 10 comprises: with the corresponding reference current generator circuit 1R of R (red) color, with the corresponding reference current generator circuit 1G of G (green) color and with the corresponding reference current generator circuit 1B of B (indigo plant) color.In addition, row driver 10 comprises white propertional regulator circuit 2R, 2G and 2B, is used to regulate R separately, the G of reference current generator circuit 1R, 1G and 1B and the reference current of B color.
White propertional regulator circuit 2R is made up of current reversal circuit 3R and 8 D/A converter circuit 4R.White propertional regulator circuit 2G is made up of current reversal circuit 3G and 8 D/A converter circuit 4G, and white propertional regulator circuit 2B is made up of current reversal circuit 3B and 8 D/A converter circuit 4B.Reference current Ir, Ig and the Ib of self-reference current generator circuit 1R, 1G and 1B are provided to white propertional regulator circuit 2R, 2G and 2B current reversal circuit 3R, 3G and 3B separately in the future.Each 8 D/A converter circuit 4R, the 4G and the 4B that are made up of current mirror circuit regulate reference current.Therefore, D/A converter circuit 4R, 4G and 4B produce reference current (hereinafter being referred to as " reference drive current ") Iro, Igo and Ibo, and it is conditioned respectively corresponding to R, G and B color.
Be stored in the register 7 with R, G and the corresponding data of B color.Temporarily be stored in the nonvolatile memory of MPU9 etc. by the data that the outside offered MPU9, then data be sent to register 7, thereby data are arranged in the register 7.Be converted to the analogue value by the data that data are arranged among D/A converter circuit 4R, 4G and the 4B and will be stored in the register 7, produce reference drive current Iro, Igo and Ibo.Temporarily be stored in the nonvolatile memory of MPU9 etc. by the data that the outside offered MPU9, then data be sent to register 7 data are arranged in the register 7.
Reference drive current Iro, Igo that is produced by white propertional regulator circuit 2R, 2G and 2B and Ibo be the input side transistor of driving and R, G and the corresponding current mirror circuit 5R of B color, 5G and 5B respectively.Therefore, current mirror circuit 5R, 5G and 5B are assigned to its outgoing side transistor with reference drive current Iro, Igo and Ibo, and the output connection that corresponds respectively to R, G and B color is brought in described transistor is set.
Incidentally, because white propertional regulator circuit 2R, 2G have identical circuit structure with 2B, and it is identical with the current mirror circuit 5R that is connected to white propertional regulator circuit 2R on circuit structure with 5B to be connected respectively to the current mirror circuit 5G of white propertional regulator circuit 2G and 2B.So, the current mirror circuit 5G and the 5B that are used for G and B color are not shown in Fig. 1.As shown in Figure 1, though the basic circuit structure of reference current generator circuit 1R, 1G and 1B is identical, the transistorized channel width ratio that constitutes current mirror circuit is different.
In the following description, reference current generator circuit 1R, white propertional regulator circuit 2R and current mirror circuit 5R will mainly be described.Because the basic circuit structure of reference current generator circuit 1G and 1B and operation and reference current generator circuit 1R's is similar, the basic circuit structure of white propertional regulator circuit 2G and 2B and operation are similar with white propertional regulator circuit 2R's, and the operation of current mirror circuit 5G and 5B and current mirror circuit 5R's is similar, then omits the circuit structure that is used for G and B color and the detailed description of operation.
Each reference current generator circuit 1R, 1G and 1B all are the constant current circuits that are used for output current (reference current), and it changes corresponding to the variation of environment temperature.Each reference current generator circuit is made up of with the reference current output circuit 13 that is connected load circuit 12 current mirror circuit 11, the load circuit (current mirror circuit) 12 that serves as the active load of current mirror circuit 11.
For example, diode D is made of (diode-connected) transistor that the diode form connects, and producing voltage VBE, described voltage has negative temperature characterisitic and corresponding with the dead band voltage (band gap voltage) between transistorized base stage and emitter.Between the source electrode of the input side N-channel MOS transistor T N1 of current mirror circuit 11 and ground GND, insert diode D.In addition, between the source electrode of the outgoing side N-channel MOS transistor T N2 of current mirror circuit 11 and ground GND, insert resistor R with positive temperature characterisitic.
The grid of transistor T N1 and TN2 is connected the drain electrode of transistor T N1 jointly, and the drain electrode of transistor T N2 connects respectively as the P channel MOS transistor TP1 of the current mirror circuit of load circuit 12 and the public grid of TP2.Load circuit 12 is connected to power lead+VDD by transistor T P1 and TP2.The transistor T P2 of load circuit 12 is input side transistors that the diode form connects, and transistor T P1 is the outgoing side transistor of same current mirror circuit.
Reference current output circuit 13 is made up of outgoing side P channel MOS transistor TP3, and the transistor T P2 of itself and load circuit 12 forms current mirror together.
In above-mentioned circuit structure, by input side transistor T P2 and outgoing side transistor T P1, with the current feedback of the outgoing side transistor T N2 of current mirror circuit 11 input side transistor T N1 to current mirror circuit 11 as the load circuit 12 of the active load of current mirror circuit 11.Input side transistor T N1 by current mirror circuit, to outgoing side transistor T N2 provide and diode D and resistor R between the corresponding electric current of voltage difference, this diode D has the negative temperature characteristic with temperature change, and this resistance has temperature variant positive temperature characterisitic.Therefore, can stably produce the big electric current with predetermined temperature coefficient of being determined by function, this function has reflected the positive and negative temperature characterisitic among the outgoing side transistor T N2.
Difference between reference current generator circuit 1R, 1G and the 1B is the transistor T N1 of current mirror circuit 11 and the channel width ratio of TN2.That is, the channel width ratio of the transistor T N1 of the channel width ratio of the transistor T N1 of the channel width ratio of the transistor T N1 of reference current generator circuit 1R and TN2, reference current generator circuit 1G and TN2 and reference current generator circuit 1B and TN2 is respectively 1: 18,1: 13 and 1: 4.
Incidentally, when the transistorized grid width of input side transistor and outgoing side is identical, can realize channel width arbitrarily (grid width) ratio 1 of the current mirror circuit 11 of each reference current generator circuit: n (n is not less than 2 integer) by a plurality of (n) outgoing side transistor in parallel.
As shown in Figure 1, the current reversal circuit 3R of white propertional regulator circuit 2R is made of current mirror circuit, and described current mirror circuit is made up of N raceway groove input side MOS transistor TN3 and outgoing side MOS transistor TN4.Connect transistor T N3 according to the diode form, and its drain electrode links to each other with the drain electrode of the P channel MOS transistor TP3 of reference current output circuit 13.Reference current Ir is offered transistor T N3.
The drain electrode of transistor T N4 links to each other with the drain electrode of the input side transistor T P4 of the current mirror circuit of D/A converter circuit 4R, and its source ground.
Therefore, will be input to current reversal circuit 3R, thereby be reversed inverse current (sink current) and export as image current by the reference current Ir of reference current output circuit 13 output.Inverse current is offered the drain electrode of the input side transistor T P4 of D/A converter circuit 4R.Electric current I r drives the transistor T P4 of back.
D/A converter circuit 4R regulates reference current according to the data that are stored in the register 7, and exports adjusted reference drive current Iro.Incidentally, because D/A converter circuit 4R is the current switch D/A converter with current mirror circuit structure, then D/A converter circuit 4R amplifies reference current, and utilize on-off circuit, produce as the adjusted analog-converted electric current with reference to drive current Iro by transistorized one of them the electric current of the outgoing side of selecting current mirror circuit, this on-off circuit is controlled ON/OFF according to the digital value that is arranged in the register 7.
Promptly, form by single input side transistor and a plurality of (n) outgoing side transistor (n is corresponding to the number of outlet terminal) 1: n and forming in the current mirror circuit that reference current distributes the type circuit, n outgoing side transistor partly replaced by n current switch D/A converter.Switch each D/A converter transistorized electric current of outgoing side partly according to digital value, and be assigned to the outlet terminal pin respectively as the electric current of analog-converted.
As shown in Figure 1, provided the part that produces the analog-converted electric current, to 6m, each conversion block comprises a plurality of outgoing side transistors as D/A conversion block 6a, provides described outgoing side transistor corresponding to the outlet terminal pin with respect at least one input side transistor T Na.
Each D/A conversion block 6a is made up of a plurality of outgoing side transistors to 6m, described transistor and N raceway groove input side MOS transistor TNa constitute current mirror circuit together, and are weighted with the corresponding number that is connected the transistorized on-off circuit (not shown) of outgoing side respectively corresponding to the weight of 8 video datas will changing.
The drain electrode of transistor T Na links to each other with the output of D/A converter circuit 4R, and is driven by adjusted reference drive current Iro.The source ground of transistor T Na.
By utilizing reference current to distribute type D/A converter circuit to form current mirror circuit 5R, can in the circuit that provides as the row driver 10 of IC, reduce size from the reference current divider to the D/A converter circuit.
At each D/A conversion block 6a in 6m, the transistorized electric current output of outgoing side is selected by on-off circuit, come ON/OFF to control this on-off circuit corresponding to 8 video datas, and produce the synthetic output of selected output current, as the analog-converted value from register 8.The electric current of analog-converted is provided to the outlet terminal PR1 of D/A conversion block 6a to 6m ... PRi ... PRm.
Incidentally, the transistorized source ground of the outgoing side of D/A conversion block.
The result, at its outlet terminal PR1, ... PRi, ... on the PRm, D/A conversion block 6a to 6m by amplifying reference drive current Iro according to each video data constantly, produce with from the brightness corresponding drive current (be generally inverse current) of MPU9 by the video data DAT of register 9 receptions.These drive currents are outputed to m the data line (alignment) of the R color that is used for the organic EL plate of active matrix type (not shown).Therefore, by data line be contained in the charge capacitor C that is used for the R color, separately drive current is sent to image element circuit, to drive the organic EL in the image element circuit.
The driving operation that is used for G and B color of D/A conversion block and the class of operation that is used for the R color seemingly, reference drive current Igo and Ibo that its response is produced by white propertional regulator circuit 2G and 2B.
Incidentally, at power lead+Vcc and each D/A conversion block 6a outlet terminal PR1 to 6m ... PRi ... be provided with the analog switch SW of the constant voltage that is used to reset between the PRm.
The input end of considering circuit is the grid of transistor T N2 of the current mirror circuit 11 of reference current generator circuit 1R, output terminal is the drain electrode of transistor T N2, the grid voltage of transistor T N2 changes corresponding to the change of supply voltage, according to the temperature characterisitic of the numerical value of resistor R, the change of described supply voltage is caused by environment temperature.The drain electrode output current driving transistors TP2 of transistor T N2, therefore, transistor T P1 current mirror connects transistor T P2.The drain electrode of transistor T P1 connects the grid of transistor T N2 by its diode that connects input side transistor T N1.Therefore, formed backfeed loop from the drain electrode of transistor T P1 to the grid of transistor T N2.
On the other hand, the grid voltage of input side transistor T N1 changes corresponding to the change of supply voltage, and it changes corresponding to environment temperature according to the temperature characterisitic of diode D.
The result, come the input voltage of FEEDBACK CONTROL transistor T N2 in such a way: this voltage is identical with the drain voltage definite corresponding to the drain current of transistor T N2, produces described drain current corresponding to the temperature variation of the difference between the voltage VR of the voltage VBE of foundation diode and resistor R.
Therefore, when the drain voltage of the grid voltage of transistor T N2 and transistor T P1 is identical corresponding to the grid voltage of transistor T N2, stablized reference current generator circuit 1, the grid voltage of described transistor T N2 produces corresponding to temperature variation.
With more detailed description, suppose under the uniform temperature that below the voltage VD of diode D (VD is the terminal voltage VBE of diode D) increases and the voltage of resistor R becomes and is lower than this reference value from reference value.In this case, increase the drain current of transistor T N2, therefore reduced the drain voltage of its load.Therefore, increased source grid (source-gate) voltage difference of transistor T P2, so increased its source-drain electrode (source-drain) electric current.As a result, also increased the source-drain electrode electric current of transistor T P1.Therefore, the drain voltage of transistor T N1 reduces corresponding to the reduction of transistor T N2 drain voltage.When the drain voltage of transistor T N1 and TN2 under every kind of temperature equates, equalization operation, and hold it under the balanced state.
When the voltage difference between the voltage VR of the voltage VD of diode D and resistor R during, above-mentioned operation will be reversed along direction that the gate-source voltage of transistor T N2 reduces.
In this case, because the voltage VD of diode D has negative temperature coefficient, and the voltage VR of resistor R has positive temperature characterisitic, and then the gate-source voltage of transistor T N2 becomes the summation of the temperature characterisitic of voltage VD and voltage VR.The temperature characterisitic summation depends on the working current ratio of current mirror circuit 11.
Now, channel width (grid width) ratio when the current mirror circuit 11 of reference current generator circuit 1 is 1: during n, will consider to use n as parameter.
Because reference current generator circuit 1 has the backfeed loop of above addressing, the equation (1) below then setting up:
VGS1+VD＝VGS2+ID2·R ...(1)
Wherein, VGS1 and VGS2 are transistor T N1 and TN2 gate-source voltage separately, and VD is the terminal voltage VBE of diode D, and R is the resistance value of resistor R, and ID1 and ID2 are transistor T N1 and TN2 drain current separately.
VGS is expressed as with gate-source voltage:
Wherein, Vth is the threshold voltage of MOS transistor, ID is its drain current, N is the number of electrons of per unit area in the population inversion layer (population inversion layer), β is the constant that equals W/L μ nCox, W/L=channel width/channel length, μ n is an electron mobility, and Cox is the electric capacity of the per unit area of grid oxidation film.
Suppose that transistor T N1 and TN2 are paired transistors, then its threshold voltage vt h equals β, so ID1=ID2=ID.
With equation (2) substitution equation (1) and rearrangement, equation (1) can be expressed as follows again:
Wherein, N1 and N2 are respectively the number of electrons of per unit area in the population inversion layer of transistor T N1 and TN2.
Equation (3) can be expressed as follows again:
From equation (4), can know and find out that output current ID is the function of terminal voltage VD, resistor R and number of electrons N1 and N2.Therefore, output current ID depends on the temperature coefficient of VD, R, N1 and N2.From this fact, know and find out that the temperature characterisitic of output current ID can change corresponding to the temperature coefficient of VD and R by using the value of N1 and N2.
Investigate according to temperature characterisitic, when channel width (grid width) ratio that uses transistor T N1 and TN2 changes N1 and N2 as parameter, as shown in Figure 2, with respect to the output current of reference current generator circuit 1R, can access channel width (grid width) ratio to temperature characterisitic.
Among Fig. 2, horizontal ordinate indicated temperature (℃) and ordinate has been indicated the output current (A) of transistor T N2.N1: N2 is corresponding to channel width (grid width) ratio of transistor T N1 and TN2.
As the channel width ratio of transistor T N1 and TN2, i.e. N1: N2 is set to N1: N2=1:, obtain the curve A among Fig. 2 at 5 o'clock.With the increase of temperature, output current reduces.As N1: N2=1: in the time of 10, obtain curve B, it is coming down to smoothly in-50 ℃ to+50 ℃ temperature range, and increases and reduces a little from+50 ℃ with temperature.As N1: N2=1: in the time of 15, obtain curve C, although it slightly increases but still be substantial planar in-50 ℃ to+100 ℃ scope.As N1: N2=1: obtain curve D in the time of 20, its increase with temperature increases, and as N1: N2=1: in the time of 35, obtain curve E, its increase with temperature and than curve D increase more sharp-pointed.
On the basis of these temperature characteristicss, investigated temperature coefficient, described temperature coefficient can cancel Fig. 3 (a) to the luminescent substance shown in Fig. 3 (c) therein display device have characteristic in the temperature range of-10 ℃ to+70 ℃ operating temperature range.According to investigation, found for dividing other R, G and B color, N1: N2=1: 18, N1: N2=1: 13 and N1: N2=1: 4 is best with respect to the luminescent substances of the available R of being used for, G and B color now.
According to this fact, the transistor T N1 of reference current generator circuit 1R, 1G among Fig. 1 and 1B and the channel width ratio of TN2 are set to 1: 18,1: 13 and 1: 4 respectively.
By above-mentioned transistor T N1 and the channel width ratio of TN2 are set, can access Fig. 3 (a) to characteristics of luminescence Rc, Gc and the Bc shown in the middle dot-and-dash line of Fig. 3 (c).
Incidentally, owing to Fig. 3 (a) is considered to admissible scope to the change of the ratio of the temperature characterisitic shown in Fig. 3 (c) by about 2, the range of choice of channel width ratio that then is used for the transistor T N1 of R color and TN2 is in 1: 16 to 1: 20 scope, the range of choice of channel width ratio that is used for the transistor T N1 of G color and TN2 is in 1: 11 to 1: 15 scope, and the range of choice of channel width ratio that is used for the transistor T N1 of B color and TN2 is in 1: 2 to 1: 6 scope.
As a result, the reference current of each reference current generator circuit 1R, 1G and 1B changes corresponding to environment temperature, and the adjusted reference current of each white propertional regulator circuit 2R, 2G and 2B also similarly changes.The video data that response is provided by MPU9 by register 7, by amplifying the reference drive current that white propertional regulator circuit 2 produces, each is carved on its outlet terminal, each D/A transform piece 6a to 6m produce and organic EL brightness is corresponding, as the drive current of inverse current.Therefore, by row side outlet terminal (row pin), drive current is outputed to the image element circuit of organic EL plate.
Shown in the characteristic Rs among Fig. 3 (a), be corrected with respect to the light characteristic of the temperature of R color, Rs is smooth in essence in-50 ℃ to+70 ℃ temperature range.For B and G color, shown in some tracing Gs and Bs among Fig. 3 (b) and Fig. 3 (c), can access the light characteristic of substantial planar in-50 ℃ to+70 ℃ the temperature range.
Owing to arrive shown in Fig. 3 (c) as Fig. 3 (a), brightness curve Rs, the Gs and the Bs that are used for R, G and B color with respect to temperature are corrected as substantial planar, even then when the temperature of display device when in-50 ℃ to+70 ℃ temperature range, changing, also can keep white balanced essence continuously.
Incidentally, the current mirror circuit 11 of each reference current generator circuit 1R, 1G and 1B comprises: be connected in series to the transistorized diode of input side and be connected in series to the transistorized resistor of outgoing side.Yet, replace diode and resistance, can connect passive element with temperature coefficient, it is connected in series to the side transistor of input and output separately of current mirror circuit 11 according to opposite direction.
In addition, should be noted that, clearly illustrate that the channel width ratio of current mirror circuit 11 is corresponding to its input side and the transistorized working current ratio of outgoing side as equation (4).
In addition, the N-channel MOS transistor that is used for described embodiment can be replaced by p channel transistor, and vice versa.Particularly, when the P channel MOS transistor was replaced by the N-channel MOS transistor, the transistor that is arranged in the D/A converter circuit 4 on power supply limit became the ground connection side, and transistorized source electrode connects ground wire.Yet under the situation that the N-channel MOS transistor of each D/A conversion block is replaced by the P channel MOS transistor, the transistorized source electrode of D/A conversion block becomes the ground connection side.
Although in described embodiment, the output of D/A conversion block is offered outlet terminal as drive current, but, can bring in corresponding to output connection separately the output stage current source is provided, and drive the output stage current source by the output current that utilizes the D/A conversion block, drive current is outputed to separately outlet terminal.
In addition, although the reference current generator circuit of described embodiment is made of transistor,, certainly form reference current generator circuit with bipolar transistor.When reference current generator circuit was made up of bipolar transistor, the channel width of current mirror circuit (grid width) ratio became the emitter area ratio.
In addition, although organic EL plate is the active matrix type, it is driven by the inverse current among the described embodiment, and the present invention can be used for driving the organic EL plate of active matrix type.When organic EL plate was the active matrix type, the drive current that adds the organic EL positive pole to became discharge current.
Though described color monitor, change owing to can proofread and correct temperature variant brightness, can be applied to the organic EL drive circuit of monochromatic organic EL plate according to reference current generator circuit of the present invention.
Claims (23)
1. the reference current generator circuit of an organic EL drive circuit is used for to produce drive current corresponding to the terminals pin of organic EL plate according to reference current, and the described organic EL plate of current drives, and described reference current generator circuit comprises:
First current mirror circuit comprises: input side transistor, outgoing side transistor and be connected in series to described input side transistor respectively and the transistorized passive element of described outgoing side, the temperature coefficient of described passive element are opposite on voltage characteristic; And
Be provided as second current mirror circuit of the load circuit of described first current mirror circuit, be used for the transistorized output current of described outgoing side is fed back to the transistorized input of described input side;
Wherein, according in described outgoing side transistor, produce, as with reference to the electric current of electric current, produce drive current, and select described input side transistor and the transistorized working current ratio of described outgoing side, thereby restriction is with respect to the brightness variation of the organic EL of temperature variation.
2. reference current generator circuit according to claim 1 is characterized in that selecting the working current ratio, so that in predetermined temperature range, the brightness that does not change with respect to temperature variation changes.
3. reference current generator circuit according to claim 2 is characterized in that predetermined temperature range from-10 ℃ to+70 ℃, and in predetermined temperature range, is smooth with respect to the light characteristic of temperature variation.
4. reference current generator circuit according to claim 2, also comprise and have the transistorized output circuit of an outgoing side, the outgoing side transistor of described output circuit and the input side transistor of described second current mirror circuit are formed current mirror together, the outgoing side transistor output reference current of described output circuit, wherein, described passive element is diode and resistor.
5. reference current generator circuit according to claim 2, it is characterized in that the described input side transistor of described first current mirror circuit and the transistor of described outgoing side transistor and described second current mirror circuit are respectively MOS transistor, and the described input side transistor of described first current mirror circuit and the transistorized working current ratio of described outgoing side equal the described input side transistor and the transistorized channel width ratio of described outgoing side of described first current mirror circuit.
6. reference current generator circuit according to claim 2 is characterized in that, corresponds respectively to three primary colours described organic EL is set, and in the three primary colours each described reference current generator circuit is set.
7. reference current generator circuit according to claim 6, it is characterized in that, selection is used for the input side transistor and the transistorized channel width ratio of outgoing side of first current mirror circuit of red color from 1: 16 to 1: 20 ratio ranges, from 1: 11 to 1: 15 ratio ranges, select to be used for the input side transistor and the transistorized channel width ratio of outgoing side of first current mirror circuit of green color, and input side transistor and the transistorized channel width ratio of outgoing side of from 1: 2 to 1: 6 ratio ranges, selecting to be used for first current mirror circuit of blue color.
8. reference current generator circuit according to claim 7, the described input and output side transistor that it is characterized in that constituting described first current mirror circuit is paired transistor.
9. an organic EL drive circuit is used for according to reference current, produces drive current corresponding to the pin of terminals separately of organic EL plate, and utilizes drive current to drive described organic EL plate, and described organic EL drive circuit comprises:
The reference current adjuster circuit of response reference current is used to produce adjusted reference drive current, produces described drive current according to adjusted reference drive current; And
Reference current generator circuit is used to produce reference current, and described reference current generator circuit comprises:
First current mirror circuit comprises input side transistor, outgoing side transistor and is connected in series to described input side transistor respectively and the transistorized passive element of described outgoing side, and the temperature coefficient of described passive element is opposite on voltage characteristic; And
Be provided as second current mirror circuit of the load circuit of described first current mirror circuit, be used for the transistorized output current of described outgoing side is fed back to the transistorized input of described input side,
Wherein, according to produce at described outgoing side transistor, as electric current with reference to electric current, produce drive current, and select described input side transistor and the transistorized working current ratio of described outgoing side, so that the restriction organic EL is with respect to the brightness variation of temperature variation.
10. organic EL drive circuit according to claim 9 is characterized in that selecting the working current ratio, so that in predetermined temperature range, the brightness that does not change with respect to temperature variation changes.
11. organic EL drive circuit according to claim 10 is characterized in that predetermined temperature range from-10 ℃ to+70 ℃, and in predetermined temperature range, is smooth with respect to the light characteristic of temperature variation.
12. organic EL drive circuit according to claim 10, it is characterized in that described reference current generator circuit also comprises having the transistorized output circuit of an outgoing side, the outgoing side transistor of described output circuit and the input side transistor of described second current mirror circuit are formed current mirror together, the outgoing side transistor output reference current of described output circuit, wherein, described passive element is diode and resistor.
13. organic EL drive circuit according to claim 10, it is characterized in that the described input side transistor of described first current mirror circuit and the transistor of described outgoing side transistor and described second current mirror circuit are respectively MOS transistor, and the described input side transistor of described first current mirror circuit and the transistorized working current ratio of described outgoing side equal the described input side transistor and the transistorized channel width ratio of described outgoing side of described first current mirror circuit.
14. organic EL drive circuit according to claim 10 is characterized in that corresponding respectively to three primary colours described organic EL is set, and in the three primary colours each described reference current generator circuit is set.
15. organic EL drive circuit according to claim 14, it is characterized in that from 1: 16 to 1: 20 ratio ranges selecting being used for the input side transistor and the transistorized channel width ratio of outgoing side of first current mirror circuit of red color, from 1: 11 to 1: 15 ratio ranges, select to be used for the input side transistor and the transistorized channel width ratio of outgoing side of first current mirror circuit of green color, and input side transistor and the transistorized channel width ratio of outgoing side of from 1: 2 to 1: 6 ratio ranges, selecting to be used for first current mirror circuit of blue color.
16. organic EL drive circuit according to claim 15, also comprise the first D/A converter circuit and the second D/A converter circuit, wherein, the described first D/A converter circuit is set in described reference current adjuster circuit, so that by regulating reference current according to the data that are provided with, thereby produce adjusted reference drive current, adjusted reference drive current and the video data of described second D/A converter circuit response, described terminals pin corresponding to described organic EL plate, produce drive current, or produce the electric current that has therefrom obtained drive current.
17. organic EL drive circuit according to claim 16, it is characterized in that the described second D/A converter circuit is by comprising that transistorized the 3rd current mirror circuit of an input side transistor and a plurality of outgoing side forms, adjusted reference drive current is input to the input side transistor of the 3rd current mirror circuit, the described second D/A converter circuit is according to the digital value of video data, by switching the transistorized electric current of described outgoing side of described the 3rd current mirror circuit, produce electric current corresponding to a plurality of analog-converted of described terminals pin separately.
18. organic EL drive circuit according to claim 17, it is characterized in that described reference current adjuster circuit also comprises the current reversal circuit, the described first D/A converter circuit is by comprising that transistorized the 4th current mirror circuit of an input side transistor and a plurality of outgoing side forms, and the transistorized reference current of input side that response is provided to the 4th current mirror circuit by described current reversal circuit, the electric current of generation analog-converted in a plurality of described outgoing side transistor of described the 4th current mirror circuit.
19. organic EL drive circuit according to claim 18, it is characterized in that described current reversal circuit is made up of the 5th current mirror circuit, described first current mirror, described the 3rd current mirror circuit and described the 5th current mirror circuit are made up of the N-channel MOS transistor respectively, and described second current mirror circuit and the 4th current mirror circuit are made up of the P channel MOS transistor respectively.
20. an organic EL display apparatus comprises:
Organic EL drive circuit has reference current adjuster circuit and reference current generator circuit, is used for according to reference current, produces drive current corresponding to the pin of terminals separately of organic EL plate, and drives described organic EL plate;
Described reference current adjuster circuit response reference current is used to produce adjusted reference drive current, produces described drive current according to adjusted reference drive current; And
Described reference current generator circuit is used to produce reference current, and described reference current generator circuit comprises:
First current mirror circuit comprises input side transistor, outgoing side transistor and is connected in series to described input side transistor respectively and the transistorized passive element of described outgoing side, and the temperature coefficient of described passive element is opposite on voltage characteristic; And
Be provided as second current mirror circuit of the load circuit of described first current mirror circuit, be used for the transistorized output current of described outgoing side is fed back to the transistorized input of described input side;
Wherein, based on the transistorized output current of described outgoing side at described first current mirror circuit, produce described reference current, and select described input side transistor and the transistorized working current ratio of described outgoing side, so that the restriction organic EL is with respect to the brightness variation of temperature variation.
21. organic EL display apparatus according to claim 20 is characterized in that selecting the working current ratio, so that in predetermined temperature range, the brightness that does not change with respect to temperature variation changes.
22. organic EL display apparatus according to claim 21 is characterized in that predetermined temperature range from-10 ℃ to+70 ℃, and in predetermined temperature range, is smooth with respect to the light characteristic of temperature variation.
23. organic EL display apparatus according to claim 22 is characterized in that described organic EL plate is the active matrix type.
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| JP2004131013 | 2004-04-27 | ||
| JP2004131013 | 2004-04-27 |
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| CNB2005100689602A Expired - Fee Related CN100437705C (en) | 2004-04-27 | 2005-04-27 | Organic EL drive circuit, reference current generator circuit and organic EL display device |
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| Country | Link |
|---|---|
| US (1) | US7372439B2 (en) |
| KR (1) | KR100705852B1 (en) |
| CN (1) | CN100437705C (en) |
| TW (1) | TW200540775A (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| GB2386462A (en) * | 2002-03-14 | 2003-09-17 | Cambridge Display Tech Ltd | Display driver circuits |
| JP4941906B2 (en) * | 2004-05-12 | 2012-05-30 | ローム株式会社 | Organic EL drive circuit and organic EL display device using the same |
| GB2435956B (en) * | 2006-03-09 | 2008-07-23 | Cambridge Display Tech Ltd | Current drive systems |
| KR101224458B1 (en) * | 2006-06-30 | 2013-01-22 | 엘지디스플레이 주식회사 | Organic light emitting diode display and driving method thereof |
| US8508522B2 (en) * | 2007-09-12 | 2013-08-13 | Rochester Institute Of Technology | Derivative sampled, fast settling time current driver |
| US8264448B2 (en) * | 2007-09-21 | 2012-09-11 | Point Somee Limited Liability Company | Regulation of wavelength shift and perceived color of solid state lighting with temperature variation |
| US7800315B2 (en) * | 2007-09-21 | 2010-09-21 | Exclara, Inc. | System and method for regulation of solid state lighting |
| US8253666B2 (en) | 2007-09-21 | 2012-08-28 | Point Somee Limited Liability Company | Regulation of wavelength shift and perceived color of solid state lighting with intensity and temperature variation |
| US8368636B2 (en) * | 2007-09-21 | 2013-02-05 | Point Somee Limited Liability Company | Regulation of wavelength shift and perceived color of solid state lighting with intensity variation |
| JP4994253B2 (en) * | 2008-01-24 | 2012-08-08 | 株式会社ジャパンディスプレイイースト | Liquid crystal display |
| KR102457206B1 (en) * | 2015-11-26 | 2022-10-21 | 엘지디스플레이 주식회사 | Display device |
| CN110543201A (en) * | 2018-05-28 | 2019-12-06 | 深圳指芯智能科技有限公司 | Current source control circuit and current source |
| JP2021196397A (en) * | 2020-06-09 | 2021-12-27 | 武漢天馬微電子有限公司 | Display device |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020135314A1 (en) * | 2001-03-26 | 2002-09-26 | Shinji Kitahara | Organic EL drive circuit and organic EL display device using the same |
| US20030184236A1 (en) * | 2002-03-27 | 2003-10-02 | Jun Maede | Organic EL element drive circuit and organic EL display device |
| JP2003288051A (en) * | 2002-03-27 | 2003-10-10 | Rohm Co Ltd | Organic el driving circuit and organic el display device |
| US20030197473A1 (en) * | 2002-04-23 | 2003-10-23 | Shinji Kitahara | Organic EL element drive circuit and organic EL display device |
| JP2004061712A (en) * | 2002-07-26 | 2004-02-26 | Rohm Co Ltd | Organic el drive circuit and organic el display device |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001034221A (en) | 1999-07-23 | 2001-02-09 | Nippon Seiki Co Ltd | Driving circuit of organic electroluminescence element |
| SG114502A1 (en) * | 2000-10-24 | 2005-09-28 | Semiconductor Energy Lab | Light emitting device and method of driving the same |
| CN100371962C (en) * | 2001-08-29 | 2008-02-27 | 株式会社半导体能源研究所 | Luminous device and its driving method, element substrate and electronic apparatus |
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2005
- 2005-04-20 TW TW094112529A patent/TW200540775A/en unknown
- 2005-04-26 US US11/114,179 patent/US7372439B2/en not_active Expired - Fee Related
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020135314A1 (en) * | 2001-03-26 | 2002-09-26 | Shinji Kitahara | Organic EL drive circuit and organic EL display device using the same |
| US20030184236A1 (en) * | 2002-03-27 | 2003-10-02 | Jun Maede | Organic EL element drive circuit and organic EL display device |
| JP2003288051A (en) * | 2002-03-27 | 2003-10-10 | Rohm Co Ltd | Organic el driving circuit and organic el display device |
| US20030197473A1 (en) * | 2002-04-23 | 2003-10-23 | Shinji Kitahara | Organic EL element drive circuit and organic EL display device |
| JP2004061712A (en) * | 2002-07-26 | 2004-02-26 | Rohm Co Ltd | Organic el drive circuit and organic el display device |
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| US7372439B2 (en) | 2008-05-13 |
| CN1691114A (en) | 2005-11-02 |
| KR100705852B1 (en) | 2007-04-09 |
| TW200540775A (en) | 2005-12-16 |
| US20050237284A1 (en) | 2005-10-27 |
| KR20060047503A (en) | 2006-05-18 |
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